In the technical field of light-emitting devices, light-emitting diodes are a widely used product and they are applicable to various technical fields, particularly applications concerning thinned and small-sized products being increasingly widened, so that an increasing number of products are being under development toward “chip scale package”. For example, a number of products that involve the use of light-emitting diodes are made with chip scale package by taking flip chip package for size reduction and thinning.
Referring to FIG. 1A, a schematic view is given to illustrate a structure of a known light-emitting diode. The known light-emitting diode 1 comprises a transparent base plate 11, epitaxial layers 12,13, an insulation layer 14, and electrodes 15, 16. In FIG. 1A, the electrodes 15, 16 are of horizontal electrode structures, and in a manufacturing process, a metal ball 17 is placed on the electrode 16 to make the electrodes 15, 16 identical in height. However, such a process of placing the metal ball 17 on the electrode 16 often results in a height difference between the electrodes 15 and 16 and this increases the product defect rate, and also increases potential risk and cost of fabrication.
Referring to FIG. 1B, an improvement over the structure of the light-emitting diode shown in FIG. 1A is provided. To overcome the issue of height difference between the electrodes 15, 16 due to the arrangement of the metal ball shown in FIG. 1A, FIG. 1B provides a structure of a light-emitting diode 1, in which a recess is formed with the insulation layer 14 and the electrode 16 is disposed in the recess in order to make the electrodes 15, 16 identical to each other in height. However, such a process requires an additional operation of forming the recess, and, in addition, since a base plate 11 used in flip chip packaging and the flip chip process of FIG. 1A both need a transparent base plate 11, alignment of the electrodes 15, 16 in making a package is difficult.
Further, if the techniques that involve flip chip packaging to achieve size reduction and thinning takes an eutectic process to form the structure of the light-emitting diode, then the equipment used for eutectic process requires a higher standard and thus, the fabrication cost may be increased.
Thus, it is an important contemporary technical issue to provide a process that makes a package that is closer to a chip size.